I have cable Internet service (and wi-fi networking) at both my house and a mother-in-law cottage. I want to get a wi-fi signal inside a metal-walled shop building/man-cave located between the two residences, so I can use a tablet or notebook when I'm hiding out from all the estrogen (wife, two daughters) at home. The shop has its own electrical service, so I can't use powerline networking to extend either network. And because of its location, the cable company won't just run an extension from either cable service; they want to sell me a third, Internet-only cable setup.
Any ideas on a good, fairly simple way to get Internet (and a wireless LAN) into the shop without burying ethernet cable or paying the cable company for service to a third location? I have read that using a wi-fi extender/repeater will cut wi-fi throughput in half for the rest of the network; is this true? Could I get around that if I set up a second wi-fi router at the house, on a different channel, and put an extender on the same channel in the shop's window? (Signal there is weak, but probably good enough for my purposes.) Or is there some other route I could take?
FWIW, I'm currently using Netgear wireless routers at both locations. Don't recall the model at the m-i-l cottage (I think it's only wireless-G), but the one here at home is a WNDR3400. Both have internal antennas, which means I'll have to replace a router if I need a directional antenna at that end. And of course the wife thinks I'm spending too much money on my computer hobby as it is.